超声对净水沉淀污泥絮体特性及对污泥回流效能的影响  

Effects of ultrasound on flocs characteristics of drinking water precipitated sludge and its impact on coagulation efficiency of sludge recycling process

作　　者：邬艳[1] 杨艳玲[1] 李星[1] 周志伟[1] 苏兆阳[1] 郭璇[1] 

机构地区：[1]北京工业大学,北京市水质科学与水环境恢复工程重点实验室,北京100124

出　　处：《中国环境科学》2014年第5期1166-1172,共7页China Environmental Science

基　　金：国家自然科学基金项目(51278005);北京市自然科学基金项目(8132007);国家水体污染控制与治理科技重大专项(2012ZX07404-003);北京工业大学研究生科技基金(ykj-2012-8771)

摘　　要：为解决污泥回流强化混凝技术存在的有毒有害物质积累的问题,取净水沉淀污泥经超声预处理后进行回流试验,考察超声作用后净水沉淀污泥絮体特性的变化及其对回流效能的影响.结果表明:超声作用后污泥溶液的温度升高,絮体粒径减小,长时间作用后粒径可降至几个?m,且粒径与声能密度呈现相关性;1,5W/mL的超声处理后,絮体Zeta电位降低,比表面积增大,10,15W/mL的超声处理后絮体Zeta电位升高,比表面积有所下降;低声能密度(1W/mL)超声处理后污泥回流可强化混凝效果,30min超声作用后污泥回流的浊度、UV254和CODMn去除率分别提高了2.7%、23.12%和10.02%,长时间高声能密度(15W/mL)超声波处理污泥回流后混凝效果反而恶化.超声技术对污泥回流后污染物的去除率有一定的提高,但超声时间和声能密度必须很好控制.In the process of enhanced coagulation by recycling sludge, drinking water precipitated sludge was pre-treated by ultrasound and the recycle trails were subsequently carried out, in order to solve the enrichment problem of poisonous and pernicious substance. The effect of ultrasound on the variability offlocs characteristics of drinking water precipitated sludge was mainly focused on, and so was its impact on coagulation efficiency of sludge recycling process. After the exposure to ultrasound, the temperature of sonicated sludge solution was raised and floc size was decreased, even could drop to a few microns after a long-term treatment. And The floc size exhibited a linear correlation with the energy density. Zeta potential of flocs of pre-sonicated sludge was decreased while specific surface was improved with energy density of 1W/mL and 5W/mL, contrastively Zeta potential was raised and specific surface was decreased with energy density of 10W/mL and 15W/mL. The coagulation efficiency was enhanced by recycling pre-sonicated sludge with a low energy density （1W/mL） within 30min ultrasonication. The improvement of turbidity, UV254 and CODMn removal was 2.7%, 23.12% and 10.02% respectively. Comparatively, a long time of ultrasonication under high energy density （15W/mL） could reduce the coagulation efficiency. Therefore, the ultrasound technique could enhance the pollutant removal, but the ultrasound time and energy density must be well controlled.

关 键 词：超声作用 污泥回流 絮体特性 比表面积 FI指数 

分 类 号：X703[环境科学与工程—环境工程]